{

  const obj1: {
      a?: number, 
      b: string,
      fn: (n:number) => void,
      fn2(c:string):string
  } = { b: '1', fn: n => {console.log(n)}, fn2(c){return c}}


  const obj2: {
      a?: number, 
      b: string,
      fn: (n:number) => void,
      fn2(c:string):string
  } = { b: '2', fn: n => {console.log(n)}, fn2(c){return c}}



  // const obj = { a: 1, b: '1', fn: n => {console.log(n)}, fn2(c){return c}}

  // obj.fn2('abc')

  // const obj = {
  //     fn() {},
  //     fn1:function(){},

  //     fn2:() => {

  //     }
  // }
}